The Explorer Edition of the glasses has both Wi-Fi and
Bluetooth radios, requiring FCC review.

The filing means that the search giant is one step closer to
shipping developer versions of the wearable technology, which is
slated to arrive at some point this year.

Engadget also noticed a reference to an "integral vibrating
element that provides audio to the user via contact with the
user's head," which the blog says likely relates to
a bone-conduction
patent from earlier this month. ("Bone
conduction" is where sound is transmitted through the bones of
the skull, another way humans hear sounds besides audio waves.)